In Chinese we use “对了”duìle to change a topic.

A：我喜欢喝茶。

  Wǒ xǐhuɑn hē chá。

  I like tea.

B：我也是。对了，这个星期六你有空吗？

  Wǒ yě shì。Duìle，zhèɡe xīnɡqīliù nǐ yǒu kōnɡ mɑ？

  Me too. By the way, do you have time on this Saturday?

“对了”duìle literally means right. It is used when you suddenly remind something. So it is usually used to change a topic, similar to ‘by the way’.